Question: Simplify the following expression: $ q = -10 + \dfrac{r - 7}{-5} $
Solution: In order to add expressions, they must have a common denominator. Multiply the first expression by $\dfrac{-5}{-5}$ $ \dfrac{-10}{1} \times \dfrac{-5}{-5} = \dfrac{50}{-5} $ Therefore $ q = \dfrac{50}{-5} + \dfrac{r - 7}{-5} $ Now the expressions have the same denominator we can simply add the numerators: $q = \dfrac{50 + r - 7}{-5} $ $q = \dfrac{r + 43}{-5}$ Simplify the expression by dividing the numerator and denominator by -1: $q = \dfrac{-r - 43}{5}$